Effect of mineral mixture supplementation on reproductive efficiency of indigenous cattle breeds

Abstract:

Mineral deficiencies in grazing cattle are a persistent problem in semi-arid rangelands of northwestern Mexico, where forage quality drops sharply during the dry season. This research examined whether a commercially available mineral mixture could improve reproductive performance in indigenous Criollo cattle at the Escuela Superior de Agricultura de Sonora, Hermosillo, from November 2022 to October 2023. Forty multiparous cows (body condition score 2.5-3.0 on a 1-5 scale) were divided equally into supplemented and control groups in a completely randomized design. The supplemented group received 80 g cow⁻¹ day⁻¹ of a mineral mix containing Ca, P, Zn, Cu, Mn, Se, and Co for 120 days during the breeding season. Serum mineral concentrations were measured monthly. The supplemented group achieved a conception rate of 72.5% versus 48.3% in controls (p<0.01). Services per conception dropped from 2.7 to 1.8, and postpartum anoestrus shortened by 19 days. Serum Zn and Se levels showed the strongest positive correlations with conception rate (r = 0.81 and 0.76, respectively). Body condition improved by 0.4 units in supplemented cows compared to 0.1 in controls. These findings confirm that targeted mineral supplementation during the breeding window can meaningfully boost reproductive output in indigenous cattle under semi-arid grazing conditions.